In catalytic burners according to the prior art it is desirable that the catalyst is used in an optimal manner, i.e. that the gases flowing through the catalyst is as homogeneous as possible. If the fuel:air ratio is biased towards excess fuel so called “hot spots” can occur, which can cause damage to the catalyst.
Thus, thorough mixing of the fuel and air is required.
In the prior art it is known to mix air and fuel before passing the mixture into the reaction chamber where it is ignited. This is no problem if the reaction chamber is sufficiently long, because any inhomogeneity is levelled out over a sufficiently long distance. However, if the reactor is shortened in order to save space or to fit it into small compartments, this levelling out cannot be achieved.